Linear motors are increasingly used when highly precise and possibly also rapid positioning of objects is involved, such as a machine part of a machine tool, for example. Via a suitable interface the primary part of the linear motor may be connected directly to the machine part or other object to be moved. In contrast to a conventional rotating motor, there is no need of providing a gear unit connected between the linear motor and the object to be driven.
Particularly suitable for applications that require especially precise positioning are ironless linear motors, in which no iron core is allocated to the at least one coil provided on the primary part. In this manner, interfering cogging torques are avoidable. However, correspondingly higher coil currents are necessary in order to be able to generate forces of sufficient magnitude at the primary part of the linear motor even in the absence of an iron core. This in turn necessitates excellent cooling of the coil or coils (hereinafter also generally referred to as coil system).
In the case of an ironless linear motor, the heat sink can simultaneously be used for accommodating the coil system of the primary part. Such an ironless linear motor is described in U.S. Pat. No. 7,057,313, for example.